This method of construction relates to that method of construction in which wall slabs and ceiling slabs are cast on site in horizontal array, and sections of ceiling slabs are connected to related groups of wall slabs by hingeable connectors, and such sections are lifted causing the connected walls to depend to a vertical position to form modules for the proposed building, and in particular the present invention discloses a new method of arranging the casting of the wall slabs and the ceiling slabs, and a new method of assembling the walls and the ceiling slabs to form mocules thru the use of access slots provided in the ceiling slabs thru which hingeable type connectors can be inserted to connect the ceiling slabs to the wall slabs.
Heretofore, buildings have been constructed according to the teaching of Johnson U.S. Pat. No. 3,494,092 in which modules comprising sections of ceiling slabs and related wall slabs extending outwardly from said sections were cast horizontally on site, with a layer of each floor level of the proposed building. The outwardly extended walls caused the module to occupy an excessively large amount of site area, and the walls prevented ceiling sections from being cast adjacent to one another, resulting in mismatches when the modules were erected into the building. In addition the outwardly extended walls interferred with placement of balconies in the design, since they could only be located where a window occurred.
An improved method was disclosed in the teaching of Johnson U.S. Pat. No. 3,828,512 in which a layer of wall slabs was cast overlying the floor slab of the proposed building, and a ceiling slab was cast overlying the layer of wall slabs, with integrally cast hingeable devices connecting the ceiling slab and hinged edge of the wall slabs. This method has the disadvantage of requiring a false forming to fill the area between edges of wall slabs to provide a casting surface for the overlying ceiling slabs, and this is a costly, time consuming operation, and the remnants of the false forming frequently stick to the edges of the wall slabs and interfer with a good seating in the erected building. In addition the connecting devices, being integrally cast with the concrete, are subject to being knocked out of position, interfer with the finishing of the concrete wall slabs, and, if they are knocked out of line, or are jammed with grout, are imposible to correct, and this condition results in very bad lifts of the modules.
Greenhalgh U.S. Pat. Nos. 3,527,008 and 3,600,870 discloses "bolts with hollow bore: thru which cables are extended to be connected to edges of underlying wall panels, with overhead winches adapted to wind up the cable and bring the edge of the wall up to the overhead ceiling panel. This requires access to the underside to effect the connection of the cable to the edge of the panel for the wall and is suitable only for exterior wall panels where there is access with the "bolts with hollow bore" being located along an outside edge.
Now in the evolution of the constructing of buildings with precast wall and ceiling slabs, the hinged connections evolved to avoid problems of matching connections between separately cast elements, and the integrally cast hinge contributed to the economy and the speed of this method of construction; and there are patents disclosing bendable metal connectors and flexible nylon ropes to effect the connections. However, they still have the basic disadvantages of being subject to being cast out of position with no way to remedy. This is less of a problem in the United States than it is a problem where unskilled labor is used to construct the units.
In addition, the above teachings show walls cast in relation to ceiling slabs where forming must be repeated for each layer. This gives room for error and requires excessive labor. In addition, the false forming is a wasteful operation.
It is the object of the present invention to provide the means of gang casting the wall elements and gang casting the ceiling elements, with the means of hingeably connecting them through access slots provided in the ceiling slabs which provide some tolerance for workman accuracy and also to eliminate the need for false forming. It is a further object of this invention to utilize the access slots to develop through the slab continuity between floor levels of the building. It is a further object to disclose the arrangement of the on site casting operation in a manner to require a minimum of site under varying conditions, and an arrangement in which a minimum movement is required for the lifting apparatus during the erection of the building.
It is a further object of this invention to disclose the means of making the section line between adjacent modules, independent of the location of the walls, and in fact developing the means of dividing the ceiling slabs at the location of "O" moment and the development of a continuous slab over a bearing wall and hence the possibility of longer spans or thinner ceiling slab thicknesses.
A further objective of the present invention is to disclose how the teaching of Johnson '775 can be effectively used to provide depressed corridor area, modeled balcony walls, and enriched architectural design, when combined with the teaching of the present invention.